A computer network is a collection of interconnected computing devices that exchange data and share resources. In a packet-based network, such as the Internet, the computing devices communicate data by dividing the data into small blocks called packets. The packets are individually routed across the network from a source device to a destination device. The destination device extracts the data from the packets and assembles the data into its original form. Dividing the data into packets enables the source device to resend only those individual packets that may be lost during transmission.
Certain devices within a network, referred to as routers, maintain routing information that describes available routes through the network. Each route defines a path between two locations on the network. Upon receiving an incoming data packet, the router examines header information within the packet to identify the destination for the packet. Based on the header information, the router accesses the routing information, selects an appropriate route for the packet and forwards the packet accordingly.
A variety of routers exist within the Internet. Network Service Providers (NSPs), for example, maintain “edge routers” to provide Internet access to the end-users. The edge routers of the NSPs often communicate network traffic to high-speed “core routers,” which may be generally viewed as forming the backbone of the Internet. These core routers often include substantially more processing resources than the edge routers, and are designed to handle high volumes of network traffic.
In addition, the NSPs often maintain “service routers” dedicated to providing services to the end-users. Examples of services that the NSP may provide include Voice over IP (VOIP), access for Asynchronous Transfer Mode (ATM) or frame relay communications, Internet protocol (IP) data services, and multimedia services, such as video streaming. NSPs often desire to isolate these services from one another for purposes of reliability. As a result, an NSP may implement each type of service with one or more dedicated service routers.
As Internet-based services become more widely adopted, this use of dedicated service routers leads to increased capital expenditures. Moreover, complexities associated with maintenance and management of separate service routers, edge routers, and core routers can be significant.